I have similar tunners in my X210(but gold) and I`m very happy with them I was lucky enough to find 3 when I did the restoration of my guitar. it is way better than gibsons. I don't see a reason to change them really.

I don't know of any that fit. But I also certainly can't say I have tried everything. If you really have your heart set on keystones I'd buy a set of the grovers and swap them out (hang onto the Electra keys if you ever want your guitar standard again). If you don't care about putting your guitar stock again, someone restoring an electra will buy those Electra keys especially if that is all that they need to change their guitar back to stock. The grovers will use the same holes leaving the extra unused screw hole open that is on the Electra keys. A few electras came with grovers - the outlaw series comes to mind. They had a extra "bullseye" decoration on the back cover though. I don't know what that was all about, but it looks pretty cool.

My x330 has the standard "butter bean" style grover rotomatics on it. I changed them out in the 90s. I really like grover rotomatics as well as locking keys on some guitars. So if I play the guitar, I will change that out. If it is to be a collector, I probably won't. They are always worth a little more to collectors if they have the stock keys - players don't usually care that much as long as they are good keys and they look right. And the electra keys really are not bad at all, they are almost as good as the grovers to me, but the grovers I have are a little smoother and maybe a slightly finer gear ratio. I think they are a slight improvement operationally.

You really have a nice vulcan there - you did a really good job on it. Do what is best for you. If you already changed pickups you might as well change the keys too. If you keep the part and ever decide to sell it, putting the originals back in will maintain the maximum resale value of your guitar. I think prices were rising on these in the last 5-10 years, but recently took a hit. Some people asking $1200 for these aren't seeing it yet but I haven't seen one sell in the past couple years around that mark. I am not trying to bust anyones chops that is currently selling them. When prices rebound (and they will) you will see stock guitar go for a premium - sometimes hundreds more - to the collectors.

Most of my Electras will appeal to players. I have a few in somewhat collectable condition as well. My x330, Leslie West, and Elvin Bishop models are players though. I don't expect anyone ever to want to pay top dollar for them, but then again I probably won't sell them unless I have to do so.